The Lucky personality type, besides hosing your stats, gives you the White Aura at character creation. That appears to help you find out of depth items. Does it also help with how good/excellent/special your loot is?

Most importantly, is it the same thing as the Lucky skill for the Skillmaster class or do they use different and compatible code blocks that effectively double your loot boosting abilities?

Lucky does not come with a life rating malus, unless they changed that in 7.0.2.
If they did, that's awful. What was Chris thinking.
Anyway, from the code:
>if (_get_skill_pts(_TYPE_ABILITY, _LUCK))
>p_ptr->good_luck = TRUE;
just like a rune knight with a rune of luck in its inventory.
Both item, ability and mutation grant the good_luck value, which do not, in fact, stack or are in any way different from oneanother.